Maintaining a certain calcium concentration is important for the proper functioning of which cells? Check all that apply.

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

i dont know it at allnow im just getting points at this pint